Controversial and worthwhile but somewhat quixotic
Two of the three deep questions about life, "What is life and how should it be defined?" are addressed in this book along with "Where might life be found?" Peter Ward and his colleague Don Brownlee addressed the third deep question, "Does life tend to evolve into intelligent life?" in their controversial book Rare Earth and came to the unpopular conclusion that intelligent life is very rare, and that overwhelmingly the vast preponderance of life in the universe is microbial. Here Ward concentrates on the possibility of microbial life in the solar system.
Let's look at Professor Ward's goals in writing this book as presented in the preface. His first goal is "to bring the public up to date on the progress in...astrobiology..."
Understandably Ward does not venture beyond the friendly (or not so friendly) confines of the solar system. Influenced as we all are by the recent discoveries of extremophiles in unlikely places on earth, Ward waxes hopeful about the possibility of microbial life under the surface of Mars, is less enthusiastic about life in the ocean under the ice cap of Europa, is pessimistic about life in the Venusian atmosphere, and is almost wildly excited about the possibility of life on the far-off Saturn moon, Titan, where he believes life could be especially exotic.
Interestingly enough Ward thinks there is alien life on earth yet to be discovered, possibly descendants of ancient RNA life. He classifies viruses as being alive and concludes, somewhat whimsically, that alien life does exist on earth since viruses are not included in the family tree of life as defined by most biologists. (One notes in passing that Richard Dawkins's recent tome The Ancestor's Tale does not include any viruses.)
I was uplifted and mostly convinced from Ward's analysis that life does indeed exist on Mars. (Yes!) Ward claims that some scientists now consider it a given, and he even hints darkly that NASA knows this (p. 189) but is keeping mum until they can present a stronger case to the public.
His second goal is "to redefine...life...." Here I am confident that other scientists will find both his grasp and reach exceeded, but I suspect his attempt to reclassify the tree of life will be a harbinger of reclassifications to come. It is here that he is at his most quixotic.
His third goal is "a rational look at what alien life might be like." He looks at life based on something other than DNA and the familiar twenty amino acids. He looks at silicone life. He looks at how life might have originated, going from "warm ponds" to clay substrates to hydrothermal vents to artificially created life.
This leads him to his fourth goal which is to speculate on how likely it is that life could arise and exist in the extreme environments elsewhere in the solar system based on the latest information. I found this part of the book intriguing and optimistic.
Ward urges us to send manned missions to both Mars and Titan because he believes that only space boots on the ground and instruments in gloved hands can best find the aliens he believes live there. Ward also makes the excellent point that only on the relatively unchanging surfaces of the moon and Mars we are likely to find evidence of early life on earth! This is because chunks of our planet flew into space and landed on the moon and Mars from a time not preserved in the geological record on earth because of weathering, etc. He even suggests that fossils of microbial life could exist in earth rocks on the moon and Mars.
There are some minuses in this book. It is not as well written or edited as his previous works. Sometimes it is the case that once a writer becomes as successful as Ward has become, editors are afraid to actually edit, and the writer himself does not read the proofs as carefully as he might. Too bad.
Another minus is his confused expression about the allocation of public funds for SETI as opposed to funds for exploring the solar system. I think Ward ought to say unequivocally that the search for extraterrestrial intelligence and the exploration of the solar system are both worthy projects that ought to receive strong support from the public. On pages 238-239 Ward actually makes fun of how humanity would benefit from a signal from intelligent extraterrestrial life. What he fails to appreciate is the deep philosophic and religious implications of such a signal. He also fails to realize that even though it may take anywhere from nine to fifty to a hundred years or more, depending on where the signal is coming from, for a stream of information to flow our way, that is still a wondrous prospect for humanity. Ward seems blithely unaware that contact of any kind from an extraterrestrial civilization would be one of the greatest events in human history. His conclusion that after such a signal we would discover that "nothing has changed" is...well, I hate to use the word "stupid" but in this case I think it really does apply.
I also didn't care for Ward's little story (pp. 236-237) about trying to give a copy of his book Rare Earth to Microsoft billionaire John Allen only to be embarrassed by SETI scientist Jill Tartar's understandable reaction. Nor did I like his making fun of Carl Sagan's now obviously unwarranted enthusiasm for macroscopic Martian life (pp. 176-179) and his later obsequious praise of the popular scientist (e.g., p. 233).
This is one of those books--Ward's 13th--that historians love because it unintentionally reveals so much about its author and his times. It's a bit breezy, a bit arrogant, and a bit quixotic, but this somewhat brazen report from the infancy of astrobiology is nonetheless an interesting and worthwhile effort.
--Dennis Littrell, author of “The World Is Not as We Think It Is”